Older Children Can Benefit From Treatment
For Childhood’s Most Common Eye Disorder
Surprising results from a nationwide clinical trial
show that many children age 7 through 17 with amblyopia
(lazy eye) may benefit from treatments that are more
commonly used on younger children.
Treatment improved the vision of many of the 507 older
children with amblyopia studied at 49 eye centers. Previously,
eye care professionals often thought that treating amblyopia
in older children would be of little benefit. The study
results, funded by the National Eye Institute (NEI),
part of the National Institutes of Health (NIH), appear
in the April issue of Archives of Ophthalmology.
“Doctors can now feel confident that traditional treatments
for amblyopia will work for many older children, said
Paul A. Sieving, M.D., Ph.D., director of the NEI. “This
is important because it is estimated that as many as
three percent of children in the United States have
some degree of vision impairment due to amblyopia. Many
of these children do not receive treatment while they
are young,” he said.
Amblyopia is a leading cause of vision impairment in
children and usually begins in infancy or childhood.
It is a condition resulting in poor vision in an otherwise
healthy eye due to unequal or abnormal visual input
while the brain is developing in infancy and childhood.
The most common causes of amblyopia are crossed or wandering
eye (strabismus) or significant differences between
the eyes in refractive error, such as, astigmatism,
farsightedness, or nearsightedness.
Children in the study were divided randomly into two
groups. One group was fitted with new prescription glasses
only. The other group was fitted with glasses as well
as an eye patch, or the eye patch along with special
eye drops, to limit use of the unaffected eye. These
children were also asked to perform near vision activities.
The patching, near activities, and eye drops force a
child to use the eye with amblyopia. Patching was prescribed
for periods of two to six hours daily, while the eye
drops were administered daily for the children seven
though twelve years of age.
The study investigators defined successful vision improvement
as the ability to read (with the eye with amblyopia)
at least two more lines on a standard eye chart. The
study investigators found that 53 percent of children
age seven through twelve years who received both glasses
and treatment with patches and near activity met this
standard, while only 25 percent of those children in
this age group who received glasses alone met the standard.
For children age 13 through 17 years who were treated
with both glasses and patches (these children did not
get drops), 25 percent met the standard while 23 percent
of children of these ages who received only glasses
met the standard.
The study also revealed that among children age 13
through 17 years who had not been previously treated
for amblyopia, 47 percent of those who were treated
with glasses, patching and near activities improved
two lines or more compared with only 20 percent of those
treated with glasses alone. Despite the benefits of
the treatment, most children, including those who responded
to treatment, were left with some visual impairment.
They did not obtain “20/20” vision.
Rates of Success Treating Children With Amblyopia In
Clinical Trial.*
|
Treatment Group ** |
Optical Correction Group (glasses
only) |
Ages seven through 12 |
53 percent |
25 percent |
Ages 13 through 17, no prior treatments |
47 percent |
20 percent |
Ages 13 through 17 |
25 percent |
23 percent |
* The standard for success in the trial was a child’s
ability to read at least two more lines on a standard
eye chart using the eye with amblyopia. This may not
be the maximum possible benefit that can be achieved
with treatment.
** Treatment was eye patching, special eye drops, and
near vision activities for ages seven through 12; eye
patching and near activities for ages 13 through 17.
“This study shows how important it is to screen children
of all ages for amblyopia.” said study co-chairman Richard
W. Hertle, M.D., Children’s Hospital of Pittsburgh.
Commented co-chairman Mitchell M. Scheiman, O.D., Pennsylvania
College of Optometry, “This study shows that age alone
should not be used as a factor to decide whether or
not to treat a child for amblyopia. The opportunity
to treat amblyopia does not end with the pre-school
years.”
It is not known, say the authors of the current study,
whether vision improvement will be sustained in these
children once treatment is discontinued. The NEI is
supporting a one-year, follow-up study to determine
the percentage of amblyopia that recurs among the children
who responded well to treatment, as well as many other
clinical studies of amblyopia at eye centers nationwide.
Dr. Sieving also commented that the current study results
are “a wonderful example of the adaptability of the
human visual system and brain. The NIH is exploring
ways to take advantage of this adaptability in order
to better understand and treat vision problems and other
neurological conditions."
The study described in this release was conducted by
the NEI-funded Pediatric Eye Disease Investigator Group.
The Group focuses on studies of childhood eye disorders
that can be implemented by both university-based and
community-based practitioners as part of their routine
practice. The study was coordinated by the Jaeb Center
for Health Research in Tampa, Florida. A list of study
centers is attached.
For background information regarding amblyopia, please
visit www.nei.nih.gov/ats3/background.asp.
A list of current study centers is available online
at www.nei.nih.gov/ats3/centers.asp.
The National Eye Institute is part of the National
Institutes of Health (NIH) and is the Federal government's
lead agency for vision research that leads to sight-saving
treatments and plays a key role in reducing visual
impairment and blindness. The NIH is an agency of
the U.S. Department of Health and Human Services. |